public function register_comment()
 {
     $comment = new BlogComment(_post('blog_comment'));
     $comment->trim();
     if ($comment->validate_register()) {
         $comment->user_id = User::get_login_id();
         $comment->save();
     } else {
         $this->flash->add('message_error', $comment->errors->get_messages());
     }
     $this->redirect_to('/blog/view/' . _post('blog_comment', 'blog_id'));
 }